What works so far

It can start services in sync mode (i.e. wait until they terminate,
to get around race conditions for static initializations)

There is a companion utility "msvc" that can be used much in the
same way as the svc from daemontools. Communication works over two
fifos, /etc/minit/in and /etc/minit/out. Those have to exist before
minit is started and they should be owned by root and have mode 600.

There is a companion utility "pidfilehack" that can be used to do
stuff like run ssh, wait a while, read the PID off /var/run/sshd.pid and
tell minit this PID so it will know when sshd exits and can restart it.

It can pipe stdout to a dedicated log process.

Wishlist

(in no particular order)

is able to boot off a completely read-only system (i.e. does not
modify file system) [CHECK!]

contains a robust logging system [CHECK!]

configuration like /var/qmail, not like inittab
(i.e. each option in a separate file, no parsing) [CHECK!]

minimal memory and disk footprint [CHECK!]

dependencies, i.e. a service can specify that it depends on a number
of other services and init will start those automatically. [CHECK!]

static initializations are handled by a separate process (to keep
init memory footprint low). [turned out to be not much code]

an easy way to extract the PID of a given service from minit, so
shell scripts can send signals to daemons. [CHECK!]

an easy way to tell init not to restart a given process [CHECK!]

an easy way to tell init to start an additional service [CHECK!]

By "easy way" I mean that the process is readily automatable, i.e. a
single command line, not that it is especially easy to understand for
Unix newbies.